Seven or more degrees of freedom robotic manipulator having at least one redundant joint

ABSTRACT

A robotic treatment delivery system including a linear accelerator (LINAC), and a robotic manipulator coupled to the LINAC. The robotic manipulator is configured to move the LINAC along seven or more degrees of freedom, at least one of the seven degrees of freedom being a redundant degree of freedom.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/096,728, filed Sep. 12, 2008, the entire contents of which are herebyincorporated by reference herein.

TECHNICAL FIELD

Embodiments of the present invention pertain to the field of roboticmanipulators used in medical applications.

BACKGROUND

Conventional robots are designed to do exactly the same thing over andover again, such as in an assembly line for assembly. These robots areprogrammed and configured to repeat a given motion to perform a specificfunction. Robots are often implemented to perform a lot of functions,more efficiently, and often more precisely than humans.

Conventional robots, typically, include one or two robotic arm. Theserobotic arms can have multiple segments that help facilitate movement indiffering degrees of freedom (DOF). Some conventional robots employ acomputer to control the segments of the robotic arm by activatingrotation of individual step motors connected to corresponding segments.Other designs may use hydraulics or pneumatics to actuate movement inthe arm segments. Computers allow precise, repeatable movements of therobotic arm.

Prior Selectively Compliant Articulated Robot Arm (SCARA) robots operatewith 4 or fewer degrees of freedom (“DOF”). In other words, theserobotic arms are designed to move along 4 or fewer axes. A typicalapplication for a conventional robotic arm is that of pick-and-placetype machine. Pick-and-place type machines are used for automationassembly, automation placing, printed circuit board manufacturing,integrated circuit pick and placing, and other automation jobs thatcontain small items, such as machining, measuring, testing, and welding.These robotic arms include an end-effector, also known as roboticperipheral, robotic accessory, robot or robotic tool, end-of-arm (EOA)tooling, or end-of-arm device. The end-effector may be an implement suchas a robotic gripper, press tool, paint gun, blowtorch, deburring tool,arc welding gun, drills, etc. These end-effectors are typically placedat the end of the robotic arm and are used for uses as described above.One common end-effector is a simplified version of the hand, which cangrasp and carry different objects. Such end effectors typically supportmaximum payloads ranging from 3 kg-20 kg (6.61-44.09 pounds).

Another type of robot that has been implemented in positioning of aradiation source of a radiation treatment system includes an articulatedrobotic arm for positioning a radiation source, such as a linearaccelerator (LINAC), mounted at a distal end of the articulated roboticarm, for selectively emitting radiation, such as described in U.S. Pat.No. 5,207,223 to Adler.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are illustrated by way of example,and not by way of limitation, in the figures of the accompanyingdrawings and in which:

FIG. 1 illustrates one embodiment of a robotic treatment delivery systemincluding a robotic arm having seven degrees of freedom.

FIG. 2 illustrates another embodiment of a robotic treatment deliverysystem having a redundant joint.

FIG. 3A illustrates one embodiment of a robotic treatment deliverysystem 300 including a vertically-mounted robotic arm having sevendegrees of freedom in a first position along the first axis.

FIG. 3B illustrates another embodiment of the robotic treatment deliverysystem of FIG. 3A in a second position along the first axis.

FIG. 3C illustrates another embodiment of a robotic treatment deliverysystem 350 including a robotic arm having six degrees of freedomhorizontally mounted on a linear track for a seventh degree of freedom.

FIG. 4A illustrates a top side view of a conventional robotic treatmentdelivery system in a first position relative to a treatment couch.

FIG. 4B illustrates a top side view of a robotic treatment system in thefirst position relative to the treatment couch, according to oneembodiment.

FIG. 4C illustrates a top side view of the conventional robotictreatment delivery system of FIG. 4A in a second position relative tothe treatment couch.

FIG. 4D illustrates a top side view of the robotic treatment deliverysystem of FIG. 4B in the second position relative to the treatmentcouch, according to one embodiment.

FIG. 5 is a perspective drawing illustrating a workspace of a robotictreatment delivery system, according to one embodiment.

FIG. 6 illustrates one embodiment of a method for positioning a medicaltool using a robotic manipulator.

FIG. 7 illustrates another embodiment of a method for maintaining amedical tool at the fixed position.

FIG. 8 illustrates a block diagram of one embodiment of a treatmentsystem that may be used to perform radiation treatment in whichembodiments of the present invention may be implemented.

DETAILED DESCRIPTION

Described herein is an apparatus having a medical tool coupled to arobotic manipulator that can move the medical tool along seven or moredegrees of freedom, the robotic manipulator having at least oneredundant joint. In the following description, numerous specific detailsare set forth such as examples of specific components, devices, methods,etc., in order to provide a thorough understanding of the presentembodiments. It will be apparent, however, to one skilled in the artthat these specific details need not be employed to practice the presentembodiments. In other instances, well-known materials or methods havenot been described in detail in order to avoid unnecessarily obscuringthe present embodiments.

The robotic manipulator can position a medical tool attached to therobotic manipulator in seven or more DOF. The robotic manipulatorincludes multiple rigid links, interconnected by joints, to move themedical tool to move the medical tool in the seven or more DOF. One ofthe rigid links includes an additional joint (also referred to herein asredundant joint). The multiple rigid links, interconnected by joints,allows either rotational or translational displacement of the medicaltool. In one embodiment, the seven DOF includes at least one redundantDOF. The additional joint may be used to move the medical tool in oneredundant DOF. For example, multiple rigid links, interconnected byjoints, may be used to move the medical tool in six DOF, and anadditional joint may be used to move the medical tool in the seventhDOF, the seventh DOF being a redundant DOF. Alternatively, the multiplerigid links, interconnected by joints, may be used to move the medicaltool in more than seven DOF, where two additional joints of one of therigid links are used to move the medical tool in two redundant DOF.

The robotic manipulator may be used in a robotic treatment deliverysystem for adjusting a position and orientation of a radiation sourceduring, for example, therapeutic radiation treatment. The robotictreatment delivery system includes the robotic manipulator, such as anarticulated robotic arm, to position and orient the radiation source,such as a LINAC, in a three-dimensional (3D) space. However, unlike theconventional robotic treatment delivery system, the robotic manipulatorof the embodiments described herein includes one or more additionaljoints than used in the conventional robotic arm having six DOF to movethe medical tool along the seventh or more DOF. For example, by addingan additional joint on the link between the third axis (A3) and thewrist assembly, the robotic manipulator can position the joints suchthat a greater range of motion is capable without putting the patient ortreatment couch in danger of collision with the robotic manipulator, ascompared to the conventional robotic arm. A similar result may beachieved by adding a third joint at the location of the first and secondaxes (A1 and A2) to allow the robotic manipulator to rotate the bulk ofthe robotic manipulator, for example, towards the floor. Using thisexample, the robotic manipulator can position the medial tool atmultiple heights, for example, the robotic manipulator may position aLINAC to a low position for high isocenters, or to a high position forlow isocenters.

Since the embodiments described herein include one or more redundant DOFof the seven or more degrees of freedom, the embodiments describedherein possess more capabilities than the conventional six DOF roboticarms. While the workspace of the robotic manipulator increasessubstantially given the extra degrees of freedom, the roboticmanipulator having one or more redundant DOF provide an infinite numberof configurations for a given tool pose of the medical tool. Theworkspace is representative of the operating envelop of the roboticmanipulator. The one or more redundant DOF of the robotic manipulatormay also allow the robotic manipulator to move while the tool positionremains constant, as well as enable smooth planar motions. Theseadditional DOF may also allow motions necessary for robust obstacleavoidance. The embodiments described herein may provide more nodes andmore paths to get to the nodes (e.g., existing nodes and new nodes). Theembodiments described herein may also provide optimization of paths toget to nodes. For example, the embodiments described herein may reducethe time to traverse the nodes, as well as increase the distance marginor clearance between possible obstructions. The embodiments describedherein may also be used to position the medical tool at a fixed pointusing a robotic manipulator, and maintain the medical tool at the fixedpoint, while moving the robotic manipulator. The embodiments describedherein may also be used to maneuver the medical tool through aconstrained volume (e.g., obstacle maze) without colliding with anobject outside of the constrained volume.

It should be noted in conventional systems, a robotic arm having greaterthan six DOF has usually been avoided due to the increase complexity ofhardware and an increase in required kinematic analysis. However, theembodiments described herein may be used to avoid obstacles and therobotic manipulator may be broken down into two segments, a wristassembly, and an arm assembly to simplify the kinematic analysis of thetool position and tool orientation. For example, different methods maybe used to solve the kinematics of each segment.

It should also be noted that the embodiments described herein have beendepicted and described as robotic arms coupled to a LINAC, however, inother embodiments, other robotic manipulators and/or other medical toolsmay be used. For example, the medical tool may be an imaging source ofan imager, a surgical tool, an implantation tool, a treatment couch, orthe like.

FIG. 1 illustrates one embodiment of a robotic treatment delivery system200 including a robotic arm 202 having seven degrees of freedom. Therobotic treatment delivery system 200 includes a LINAC 203, and therobotic arm 202 having a wrist assembly 212 and an arm assembly. Thewrist assembly 212 is configured to move the LINAC 203 in threerotational DOF (Axes 5-7), and the arm assembly is configured move theLINAC 203 in four DOF (Axes 1-4), one being a redundant DOF. The armassembly includes multiple rigid links, interconnected by joints, tomove the LINAC 203 in the four DOF, including the redundant DOF.

The LINAC 203 is used to produce a beam of radiation that can bedirected to a target. The robotic arm may be a highly articulatedrobotic arm that may have multiple rotational DOF in order to properlyposition and orient the LINAC 203 to irradiate a target such as apathological anatomy with a beam delivered from many angles in anoperating volume around the patient 205. It should be noted that patient205 may be a human patient, and alternatively, an animal patient. Also,in other embodiments, other objects than a human or animal may be used.The treatment implemented with the robotic treatment delivery system 200may involve beam paths with a single isocenter (point of convergence),multiple isocenters, or without any specific isocenters (i.e., the beamsneed only intersect with the pathological target volume and do notnecessarily converge on a single point, or isocenter, within thetarget). Furthermore, the treatment may be delivered in either a singlesession (mono-fraction) or in a small number of sessions(hypo-fractionation) as determined during treatment planning. Therobotic treatment delivery system 200 delivers radiation beams accordingto the treatment plan without fixing the patient to a rigid, externalframe to register the intra-operative position of the target volume withthe position of the target volume during the pre-operative treatmentplanning phase

The LINAC 203 is rotatably attached to the wrist assembly 212, whichincludes a tool-yaw joint, a tool-pitch joint, and a tool-roll joint.The tool-yaw joint of wrist assembly 212 may be coupled to a mountingplate (not illustrated), which may be attached to the bottom of theLINAC 203. Alternatively, the tool-yaw joint of wrist assembly 212 maybe coupled directly to the bottom of the LINAC 203. The tool-yaw jointof wrist assembly 212 facilitates rotational movement of the LINAC 203in a yaw-rotation along the z-axis. The tool-pitch joint may be coupledto the tool-yaw joint and facilitates rotational movement of the LINAC203 in a pitch-rotation along the y-axis. The tool-roll joints may becoupled to the tool-pitch joint and facilitates rotational movement ofthe LINAC 203 in a roll-rotation along the x-axis. The z-axis, y-axis,and x-axis may be the axes 5-7 of the robotic arm 202.

In the depicted embodiment, the arm assembly includes a redundant-jointassembly 211, an elbow assembly 213, a first shoulder assembly 214, andsecond shoulder assembly 215. The redundant-joint assembly 211 iscoupled to the tool-roll joint of the wrist assembly 212. Theredundant-joint assembly 213 may include three drive shafts and threemotors to drive the rotational movements of the joints of the wristassembly 212. In one embodiment, the motors discussed herein may be stepmotors. Alternatively, the motors may be servo motors or other motors aswould be appreciated by those of ordinary skill in the art. The firstdrive shaft may be coupled to the tool-yaw joint and the first motor.The first motor and drive shaft drive rotational movement of LINAC 203along the yaw axis, axis 7. The second drive shaft may be coupled to thetool-pitch joint and the second motor. The second motor and drive shaftdrive rotational movement of the LINAC 203 along the pitch axis, axis 6.The third drive shaft may be coupled to the tool-roll joint and thethird motor. The third motor and drive shaft drive rotational movementof the LINAC 203 along the roll axis, axis 5. It should be noted thatthe axes may be designated in other orders of axes 5-7.

The elbow assembly 213 is coupled to the redundant-joint assembly 211 bya redundant joint, and the first shoulder assembly 214 is coupled to theelbow assembly 213 by an elbow joint. The redundant joint includes agearbox, which may be configured to drive rotational movement of theredundant-joint assembly 211 in a rotational axis, axis 4. The elbowjoint includes an elbow gearbox, which may be configured to driverotational movement of the elbow assembly 213 in a rotational axis, axis3. The shoulder assembly 214 includes a first shoulder joint, whichincludes a gearbox, which may be configured to drive rotational movementof the first shoulder assembly 214 in a rotational axis, axis 2. Thegearboxes of the additional joint, elbow joint, and shoulder joints mayfacilitate translational movement of the LINAC 203 in 3-D space. Thesecond shoulder assembly 215 is coupled to the first shoulder assembly214 by a second shoulder joint, which includes a gearbox, which may beconfigured to drive rotational movement of the second shoulder assembly215 in a rotational axis, axis 1. It should be noted that in otherembodiments, the robotic arm 202 may include other types of motionactuators than gearboxes for moving the LINAC 203, in accordance withdirections from the controller.

In the depicted embodiment, the redundant-joint assembly 211 is coupledbetween the wrist assembly 212 and the elbow assembly 213.Alternatively, the redundant-joint assembly 211 may be coupled betweenother components of the arm assembly. For example, in anotherembodiment, the redundant-joint assembly is coupled between the elbowassembly and the first shoulder assembly. In this embodiment, an elbowjoint is coupled to the wrist assembly and the elbow assembly. The elbowjoint includes an elbow gearbox to drive rotational movement of therobotic arm in a rotational axis, axis 4. Also, a redundant joint iscoupled to the elbow assembly and the first shoulder assembly. Theredundant joint includes a gearbox to drive rotational movement of therobotic arm in a rotational axis, axis 3. The first and second shoulderassemblies include the first and second shoulder joints andcorresponding gearboxes to drive rotational movement of the robotic armin the rotational axes, axis 2 and axis 1, as described above. Inanother embodiment, when the elbow assembly 213 is coupled directly tothe wrist assembly 212, the elbow assembly includes the first, second,and third drive shafts that are coupled to the tool-yaw joint,tool-pitch joint, and the tool-roll joint, respectively, and the first,second, and third motors to drive rotational movement of the tool-yaw,tool-pitch, and tool-roll joints, respectively.

The robotic arm 202 may be coupled to a mount assembly 216 by the secondshoulder joint. The mount assembly 216 may be coupled to the floor,wall, ceiling, a column, or the like. Alternatively, the robotic arm 202may be coupled directly to the floor, wall, ceiling, a column, or thelike, without the use of the mount assembly 216.

In another embodiment, the second shoulder assembly 215 includes a thirdshoulder joint having a third shoulder gearbox to drive rotationalmovement of the robotic arm in an eighth axis of the robotic arm. Inanother embodiment, the mount assembly 216 is coupled to a track mountassembly, which is coupled to a track 226. Alternatively, the secondshoulder assembly 215 may be coupled to the track mount assembly. Thetrack mount assembly and track may facilitate translational movement ofthe LINAC 203 in a substantially, linear axis. The track may behorizontally oriented or vertically oriented. This linear axis may bethe eight DOF of the robotic arm. In another embodiment, the linear axisis the seventh DOF, in place of the last rotational axis, axis 1, asdescribed above.

In one embodiment, the substantially linear DOF is a first DOF of theseven or eight DOF, meaning the DOF closest to the base end of therobotic arm, as opposed to the last DOF at the end-effector end (alsoreferred to as the business end) of the robotic arm, which is thefarthest from the base end of the robotic arm. The first DOF isconfigured to move the other six or seven rotational DOF of the roboticarm. That is, the medical tool and robotic arm may be moved along thesubstantially linear axis throughout an entire range of motion of themedical tool without movement of the medical tool along the rotationaldegrees of freedom.

The substantially linear DOF includes a substantially linear axis fortranslational movement of the medical tool along either a substantiallyvertical line in the z-axis substantially perpendicular to mutuallyorthogonal horizontal coordinate x- and y-axes or a substantiallyhorizontal line in mutually orthogonal horizontal coordinate x- andy-axes substantially perpendicular to the z-axis. In one embodiment, thetrack may be vertically oriented, for example, vertically mounted to avertical side of column. The column may be secured or mounted to thefloor of the treatment room during therapeutic radiation treatment orbelow the floor in a pit. In another embodiment, the column may besecured or mounted to the ceiling of the treatment room duringtherapeutic radiation treatment. Alternatively, the track may bevertically mounted to other structures known to those skilled in theart, such as a wall, pedestal, block, or base structure. In anotherembodiment, the track may be horizontally oriented, for example,horizontally mounted to the floor of the treatment room duringtherapeutic radiation treatment or below the floor in a pit. In anotherembodiment, the track may be secured or mounted to the ceiling of thetreatment room during therapeutic radiation treatment. Alternatively,the track may be horizontally mounted to other structures known to thoseof ordinary skill in the art.

In one embodiment, a controller (not illustrated for ease ofillustration) is coupled to the robotic arm 202 to move the robotic armand the LINAC 203 in the seven or more DOF. The robotic arm 202 may becontrolled by motion commands received from the controller. In anotherembodiment, a user interface unit is coupled to the controller tomanually move the robotic arm 202 and the LINAC 203 in the seven or moreDOF.

The above mentioned arrangement of the wrist assembly 212, elbowassembly 213, first shoulder assembly 214, second shoulder assembly 215,and mount assembly 216 facilitate the positioning of the LINAC 203 usingseven rotational DOF, including one redundant DOF. The seven DOF of therobotic arm 202 of the robotic treatment delivery system 200 mayposition and orient the LINAC 203 in substantially any place in adesired treatment area, such as a workspace within the mechanical rangeof motion of the robotic arm 202. The robotic arm 202 may position theLINAC 203 to have a tool center position (TCP), machine center, orisocenter in multiple locations within the workspace or treatment area.The motion command signals, generated by the controller, may controlcorrective motions of the robotic treatment delivery system 200 in thevarious DOF. In one embodiment, the position and orientation of theLINAC 203 with respect to the treatment couch 206 may be known, so thatcoordinated movements may be effected. In one exemplary embodiment, boththe LINAC 203 and the treatment couch 206 can be referenced to a common(or “room”) coordinate system. Alternatively, the robotic arm 202 may beconfigured to facilitate motion of the LINAC 203 along eight DOF.

In one embodiment, the eight DOF include two redundant DOF. In anotherembodiment, the eight DOF include seven rotational DOF, including oneredundant DOF, and one translational DOF. Alternatively, otherconfigurations are possible. In one exemplary embodiment, the seven DOFincludes four rotational axes for translational movement of the LINAC203 along mutually orthogonal x-, y-, and z-coordinate axes, and threerotational axes for roll-, pitch-, and yaw-rotations of the LINAC 203about x-, y-, and z-axes, respectively. In this embodiment, the fourrotational axes include one redundant rotational axis for translationalmovement of the LINAC 203. In another exemplary embodiment, the eightDOF includes five rotational axes for translational movement of theLINAC 203 along mutually orthogonal x-, y-, and z-coordinate axes, andthree rotational axes for roll-, pitch-, and yaw-rotations of the LINAC203 about x-, y-, and z-axes, respectively.

In another exemplary embodiment, the eight DOF includes four rotationalaxes for translational movement of the LINAC 203 along mutuallyorthogonal x-, y-, and z-coordinate axes, three rotational axes forroll-, pitch-, and yaw-rotations of the LINAC 203 about x-, y-, andz-axes, respectively, and a substantially linear DOF that includes asubstantially linear axis for translational movement of the medical toolalong either a substantially vertical line in the z-axis substantiallyperpendicular to mutually orthogonal horizontal coordinate x- and y-axesor a substantially horizontal line in mutually orthogonal horizontalcoordinate x- and y-axes substantially perpendicular to the z-axis.Alternatively, one or more redundant DOF may be used in otherconfigurations.

The robotic treatment delivery system 200 is configured to adjust theposition and orientation of the LINAC 203 in a 3D workspace or operatingenvelop in a treatment room under computer control, during therapeuticradiation treatment, using the controller. The controller may be coupledto the robotic arm 202, a motion tracking system 210, a user interface,an imaging system (including x-ray sources 207 and detectors 208), and apatient positioning system 212, including a treatment couch 206.Alternatively, the controller is coupled to more or less components ofthe system depicted in FIG. 1.

In one embodiment, the robotic treatment delivery system 200 may be aframeless, image-guided robot-based therapeutic radiation treatmentsystem utilizing a LINAC. Alternatively, the robotic treatment deliverysystem 200 may be other types of robot based medical systems. In oneembodiment, the radiation source is a LINAC, such as LINAC 203.Alternatively, the radiation source may be other types of radiationsources that can be mounted to the distal end of the robotic arm. In oneembodiment, the LINAC 203 is an x-ray LINAC. Alternatively, the LINAC203 may be other types of LINACs as would be appreciated by those ofordinary skill in the art.

In the depicted embodiment, the patient positioning system 212 includesthe treatment couch 206 coupled to a robotic arm 221 having a wristassembly 222, an elbow assembly 223, a shoulder assembly 224, a trackmount assembly 225, and a track 226. The robotic arm 221 is configuredto move the treatment couch in six DOF, including one substantiallylinear DOF. The robotic arm 221 includes multiple rigid links,interconnected by joints, to move the treatment couch 206 in the fiverotational DOF. The robotic arm 221 is mounted to the track 226, whichfacilitates movement of the treatment couch 206 in the substantiallylinear DOF. The wrist assembly 222 is configured to move the treatmentcouch 206 in three rotational DOF (Axes 4-6), and the elbow, shoulder,and track mount assemblies 223-225, and the track 226 are configuredmove the treatment couch 206 in three DOF, two rotational DOF and thesubstantially linear DOF.

The elbow assembly 223 is coupled to the wrist assembly 222 and theshoulder assembly 224. The track mount assembly 225 is coupled to thetrack 226 and to the shoulder joint of the shoulder assembly 214. In thedepicted embodiment, the track mount assembly 225 and track 226facilitate translational movement of the LINAC 203 in a substantiallyvertical, linear axis. The substantially vertical, linear axis (z-) maybe substantially perpendicular to the two dimensional horizontal plane(x-, y-). In one embodiment, the track may be vertically oriented, forexample, vertically mounted to a vertical side of a column. The columnmay be secured or mounted to the floor of the treatment room duringtherapeutic radiation treatment or below the floor in a pit. In anotherembodiment, the column may be secured or mounted to the ceiling of thetreatment room during therapeutic radiation treatment. Alternatively,the track 226 may be vertically mounted to other structures known tothose skilled in the art, such as a wall, pedestal, block, or basestructure.

Although the treatment couch 206 is coupled to the robotic arm 221 inFIG. 1, in other embodiments, other patient positioning systems may beused to position and orient the patient relative to the robotictreatment delivery system 200. For example, the LINAC 203 may bepositioned with respect to a treatment couch 206 that is not coupled toa robotic arm, such as a treatment couch mounted to a stand, to thefloor, to the AXUM® treatment couch, developed by Accuray Inc., ofSunnyvale, Calif., or to other patient positioning systems.

In one embodiment, the robotic arm 221 is coupled to the same controlleras the controller that controls the robotic arm 202. The controller maybe used to coordinate the movements of both the LINAC 203 and thetreatment couch 206 relative to one another. This may allow the LINAC203 to be positioned and oriented with respect to the treatment couch inadditional positions that may have been previously obstructed forconventional systems. In another embodiment, the robotic arms 202 and221 are coupled to separate controllers.

In another embodiment, the robotic treatment delivery system 200includes an x-ray imaging system. The x-ray imaging system generatesimage data representative of one or more real time or near real timeimages of the target. The x-ray imaging system may include a pair ofdiagnostic x-ray sources 207, power supplies associated with each x-rayimaging source, one or two imaging detectors 208 (or cameras), andcontroller. The x-ray imaging sources 207 may be mounted angularlyapart, for example, about 90 degrees apart, and aimed through thetreatment target (e.g., tumor within the patient) toward the detector(s)208. Alternatively, a single large detector may be used that would beilluminated by each x-ray source. In the single detector imaging system,the two x-ray sources 207 may be positioned apart at an angle less than90 degrees to keep both images on the single detector surface.

The detector(s) 208 may be placed below the treatment target, e.g., onthe floor, on the treatment couch 206, or underneath the LINAC 203, andthe x-ray imaging sources 207 may be positioned above the treatmenttarget (e.g. the ceiling of the treatment room), to minimizemagnification of the images and therefore the required size of thedetector(s) 208. In an alternative embodiment, the positions of thex-ray imaging sources 207 and the detector(s) 208 may be reversed, e.g.the x-ray imaging sources 207 below the treatment target and thedetector(s) 208 above the treatment target. In another embodiment, thedetector(s) 208 are arranged in a manner such that they move intoposition for imaging and the moved out of the way during positioning ofthe LINAC 203 or the treatment couch 206 or during delivery of theradiation beam from the LINAC 203.

The detector(s) 208 may generate the image information of the patientand send it to the controller. The controller performs all the imagingcalculations to determine the patient's position with respect to thedesired treatment position and generate corrections for the various DOF.The corrections could be automatically applied to the robotic treatmentdelivery system 200 to automatically align the LINAC 203, and/or sent tothe controller to automatically adjust the patient's position using thetreatment couch 206 and robotic arm 212 relative to the LINAC 203,and/or sent to the user interface unit for a user to manually adjust thepatient's position relative to the LINAC 206, using one or both of therobotic arms 202 and 221.

In another embodiment, the corrective motions of the robotic treatmentdelivery system 200 may be dynamically coordinated with the motions ofthe treatment couch 206 and robotic arm 221 using the controller, in away as to maximize the workspace available to the system. By dynamicallycoordinating the motions of the treatment couch 206 and the LINAC 203using the controller, the available number of treatment targetsincreases due to the increased number of orientations and positions ofthe LINAC 203 and the treatment couch 206, which are free ofobstructions, for example, by detectors 208 and/or x-ray imaging sources207, robotic arms, or other equipment within the treatment room. In thisembodiment, the robot-implemented movements of the LINAC 203 arecomplemented by the corrective motions of the treatment couch 206, sothat the relative motion between the LINAC 203 and the treatment couch206 ensures the delivery of the desired radiation pattern throughout thetarget region.

The treatment couch 206 supports the patient 205 during treatment, andmay be positioned between the two x-ray cameras and their respectivediagnostic x-ray sources of the imaging system. In one embodiment, thetreatment couch 206 may be made of a radiolucent material so that thepatient could be imaged through the treatment couch 206.

The imaging system generates, in real time or near real time, x-rayimages showing the position and orientation of the target in a treatmentcoordinate frame. The controller may contain treatment planning anddelivery software, which may be responsive to pre-treatment scan data CT(and/or MRI data, PET data, ultrasound scan data, and/or fluoroscopyimaging data) and user input, to generate a treatment plan consisting ofa succession of desired beam paths, each having an associated dose rateand duration at each of a fixed set of treatment positions or nodes. Inresponse to the controller's directions, the robotic arm moves andorients the LINAC 203, successively and sequentially through each of thenodes, while the LINAC 203 delivers the required dose as directed by thecontroller. The pre-treatment scan data may include, for example, CTscan data, MRI scan data, PET scan data, ultrasound scan data, and/orfluoroscopy imaging data.

Prior to treatment, the patient's position and orientation within theframe of reference established by imaging system may be adjusted tomatch the position and orientation that the patient had within the frameof reference of the CT (or MRI or PET or fluoroscopy) scanner thatprovided the images used for planning the treatment. In one exemplaryembodiment, this alignment may be performed to within tenths of amillimeter and tenths of a degree for all of the DOF.

The controller may also communicate with a diagnostic or treatmentplanning system, receiving pre-treatment scan data representative of oneor more pre-treatment scans of a treatment target within the patient.The pre-treatment scans may show the position and orientation of thetarget with respect to a pre-treatment coordinate system. The controllermay also receive from the imaging system (x-ray sources 207 anddetectors 208) image data representative of real time or near real timeimages of the target. The image data may contain information regardingthe real time or near real time position and orientation of the targetwith respect to a treatment coordinate system. The treatment coordinatesystem and the pre-treatment coordinate system are related by knowntransformation parameters.

The controller may include an input module for receiving 1)pre-treatment scan data representative of pre-treatment scans of thetarget, and 2) real time or near real time image data representative ofreal time or near real time images of the target. The pre-treatmentscans show the position and orientation of the target with respect tothe pre-treatment coordinate system. The near real-time images, taken bythe imaging system under the command of the controller, show theposition and orientation of the treatment target with respect to thetreatment coordinate system. The treatment coordinate system and thepre-treatment coordinate systems are related by known transformationparameters. The controller includes a TLS (target location system)processing unit that computes the position and orientation of thetreatment target in the treatment coordinate system, using thepre-treatment scan data, the real time or near real time image data, andthe transformation parameters between the pre-treatment coordinatesystem and the treatment coordinate system. The processing unit of thecontroller may also compute the position and orientation of theisocenter of the LINAC 203.

The motion tracking system 210 may be used for detecting the position ofthe LINAC 203 and/or a treatment couch 206. The motion tracking system210 may be a part of, or separate from the robotic treatment deliverysystem 200. The controller may be operatively coupled to motion trackingsystem 210 in order to calculate the position and orientation of theLINAC 203 relative to the treatment room or other predefined treatmentcoordinate system based on the data received from the motion trackingsystem. The controller may independently check the position andorientation of the LINAC against a model of surrounding obstructions toensure that the LINAC 203 does not collide with obstacles during motionof the robotic treatment delivery system 200. The controller may alsooperate to control the motion of the robotic treatment delivery system200 in a way that a treatment target within the patient's anatomyremains properly aligned with respect to a treatment beam source of theLINAC 203 throughout the treatment procedure. Controller may also beused to operate the positioning of the treatment couch 206.

The motion tracking system 210 may be a laser scanning system or anoptical tracking system disposed within the treatment room for detectingthe position of the LINAC 203 relative to the treatment room or othertreatment coordinate system. An exemplary laser scanning system may scanthe treatment room approximately 60×/sec to determine the position ofthe LINAC 203. The laser scanning system may include devices performinga single plane scanning, or two-plane scanning, or multiple-planescanning. Correspondingly, the controller may be loaded with softwareadapted for receiving information from the motion tracking system 210and calculating the position of the LINAC 203, as well as the treatmentcouch or other equipment in the treatment room, so that the robotictreatment delivery system 200 including the controller always knows theposition of the LINAC 203. The controller may be programmed toautomatically or periodically calibrate the LINAC 203 with the treatmentcouch.

In an alternative embodiment, the motion tracking system 210 includes amagnetic tracking system for tracking the position of the LINAC 203relative to the treatment coordinate system. The magnetic trackingsystem preferably includes at least one transducer attached to the LINAC203. Alternatively, other sensor systems may be used, such as aninertial sensor attached to the LINAC 203 for sensing the motions of theLINAC 203, a resolver-based sensor system, an infrared triangulationsystem, an optical encoder, or the like, as would be appreciated bythose of ordinary skill in the art. It should be noted that the motiontracking system 210 may be used for tracking the robotic arm 202, LINAC203, robotic arm 221, the treatment couch 206, a patient 205, or otherobjects within the treatment room. The motion tracking system 210 mayalso be used for tracking a target within the patient 205.

The controller may be adapted to detect a misalignment of the treatmenttarget with the isocenter of the LINAC 203 caused by patient's movementby comparing the position of the treatment target with the isocenter ofthe LINAC 203, and generate motion command signals for implementingcorrective motions of the robotic treatment delivery system 200 foraligning the treatment target with respect to the radiation treatmentsource (e.g., LINAC 203).

In another embodiment, the corrective motions of the robotic treatmentdelivery system 200 may accommodate for various motions, such asrespiratory motion; cardiac pumping motion of the patient's heart;sneezing, coughing, or hiccupping; and muscular shifting of one or moreanatomical members of the patient. In another embodiment, the robotictreatment delivery system 200 including the controller may be adapted todetect and accommodate changes in tumor geometry that may be caused bytissue deformation by comparing the real time or near real time imagewith the pre-treatment image and repositioning the LINAC 203 using therobotic arm 202 and/or the patient using the treatment couch, oradjusting the positions of the LINAC 203 and the treatment couch tocorrespond to the treatment plan.

The controller includes software for establishing and maintaining areliable communication interface with the LINAC 203. The software usesthe interface specifications developed for the LINAC 203. The controllerfurther includes software for converting the patient position andorientation information from the imaging system to appropriate units ofmovement in the DOF of motion capability of the LINAC 203. Thecontroller may include software for providing a user interface unit tothe treatment delivery system's user control console, to monitor andinitiate the motion of the robotic treatment delivery system 200 forpositioning the patient. The controller 200 may also include softwarefor detecting, reporting, and handling errors in communication orsoftware control of the LINAC 203.

The controller may include at least one user interface unit for enablingthe user to interactively control the motions or corrective motions ofthe robotic treatment delivery system 200, by implementing one or moreuser-selectable functions. The user interface unit may be a handhelduser interface unit or remote control unit. Alternatively, the userinterface unit may be a graphical user interface (GUI) on a display.

The communication links between the controller and other components ofthe robotic treatment delivery system 200 (e.g., the robotic arm 202,LINAC 203, motion tracking system 210, user interface, treatment couch206, and imaging system) may be wired links or wireless links, with abandwidth necessary for maintaining reliable and timely communications.

It should be noted that additional joint in the embodiments above hasbeen implemented in a redundant-joint assembly that is coupled betweenthe wrist assembly 211 and the elbow assembly 213, however, in otherembodiments, the redundant joint may be implemented in otherconfigurations. In one embodiment, the robotic arm includes a wristassembly that is coupled to the LINAC 203, and an arm assembly that iscoupled to the wrist assembly. The arm assembly may include one or moreredundant joints. The one or more redundant joints may be implemented inconjunction with one or more redundant-joint assemblies, or asadditional joints to the other assemblies of the arm assembly. Forexample, the depicted embodiment of FIG. 1 illustrates the additionaljoint between the wrist assembly 211 and the elbow assembly 213. Inother embodiments, the additional joint may be disposed in aredundant-joint assembly coupled between any two of the following: theelbow assembly 213, first shoulder assembly 214, second shoulderassembly 215, and the mount assembly 216. In other embodiments, theadditional joint may be implemented as an additional joint to a joint ofany one of the following: the elbow assembly 213, first shoulderassembly 214, and second shoulder assembly 215. For example, the firstand second shoulder assemblies (collectively with the mount assembly 216may be referred to as a base assembly) includes the first and secondshoulder joints. The additional joint may be added at the location ofthe first and second axes (A1 and A2) (e.g., at the base assemblyincluding the first and second shoulder joints). By adding theadditional joint at the location of the first and second shoulderjoints, the arm assembly is capable to position the joints such that agreater range of motion is capable without putting the patient ortreatment couch in danger of collision with the robotic arm or LINAC203, as compared to the conventional robotic arm. Also, by adding theadditional joint at the location of the first and second shoulderjoints, the arm assembly is capable of rotating the bulk of the roboticarm, for example, towards the floor, as illustrated in FIG. 2.

FIG. 2 illustrates another embodiment of a robotic treatment deliverysystem 250 having a redundant joint. The robotic treatment deliverysystem 250 includes the LINAC 203 coupled to a robotic arm 252. Therobotic arm 252 includes the wrist assembly 212, elbow assembly 213,first shoulder assembly 214, second shoulder assembly 215, and the mountassembly 216, as described above with respect to FIG. 1. Rather thanhaving the redundant-joint assembly 211, the robotic arm 252 includes anadditional joint 253 at the location of the first and second shoulderassemblies. It should be noted that the robotic arm 202 uses the firstand second shoulder joints to move the robotic arm 202 along the firstand second rotational axes (A1 and A2) at the base assembly and theelbow and redundant joints to move the robotic arm 202 along the thirdand fourth rotational axes (A3 and A4). The arm assembly of the roboticarm 202 includes the base assembly, which includes the first and secondshoulder joints, and three rigid links interconnected by the additionaljoint and the elbow joint. In contrast, the robotic arm 252 uses thefirst and second shoulder joints, and the additional joint 253 to movethe robotic arm 252 along the first, second, and third rotational axes(A1, A2, and A3) at the base assembly, and the elbow joint to move therobotic arm 252 along the fourth rotational axis (A4). The arm assemblyof the robotic arm 252 includes the base assembly, which includes thefirst and second shoulder joints and the additional joint 253, and tworigid links interconnected by the elbow joint. As described above, byadding the additional joint 253 at the base assembly, the bulk of therobotic arm 252 may be rotated, for example, towards the floor.

In the depicted embodiment, the robotic arm 250 is rotated from a firstposition 251 (indicated by dashed lines), to a second position 253(indicated by solid lines). These two positions 251 and 252 may be usedto position the LINAC 203 to a high position for treating lowerisocenters, and to a low position for treating higher isocenters. Forexample, the treatment couch 206 in FIG. 2 has been illustrated as beingdisposed in a high position. As such, the isocenter may be a highisocenter. In order to position the LINAC 203 in certain positions belowthe high isocenter, the robotic arm 252 may be rotated about theadditional joint 253 to position the LINAC 203 underneath the highisocenter, such as at the second position 253. However, when thetreatment couch 206 is moved to a lower position, the robotic arm 252may be rotated about the additional joint 253 to position the LINAC 203above the low isocenter, such as at the first position 251.

Although the embodiments above are described as moving the LINAC 203 androbotic arm 202 with respect to the treatment couch 206, which iscoupled to a robotic arm 221, in other embodiments, the LINAC 203 androbotic arm 202 are moved with respect to a conventional treatment couch106, which may be coupled to a conventional robotic arm, such as roboticarm 102, or a conventional treatment couch that is not coupled to aconventional robotic arm.

The embodiments of FIGS. 1 and 2 illustrate robotic arms that aremounted horizontally to a mount assembly, as well as to the floor. Inother embodiments, the robotic arms, including one or more additionaljoints may be vertically mounted, such as illustrated in FIGS. 3A and3B.

FIGS. 3A and 3B illustrates one embodiment of a robotic treatmentdelivery system 300 including a vertically-mounted robotic arm havingseven degrees of freedom in two positions 321 and 323 along the firstaxis. The robotic treatment delivery system 300 includes the LINAC 203coupled to the robotic arm 302. The robotic arm 302, like robotic arms202 and 252, includes the wrist assembly 212 and an arm assembly. Asdescribed above, the wrist assembly 212 is configured to move the LINAC203 in three rotational DOF (Axes 5-7). The depicted embodiment of thearm assembly of FIG. 3A includes an elbow assembly 313, aredundant-joint assembly 311, a shoulder assembly 314, a track mountassembly 316, and track 317. The elbow assembly 313 is coupled to thetool-roll joint of the wrist assembly 212. The elbow assembly 313 mayinclude three drive shafts and three motors, as described above withrespect to the redundant-joint assembly 211. The redundant-jointassembly 311 is coupled to the elbow assembly 313 by an elbow joint, andto the shoulder assembly 314 by a redundant joint. The shoulder assembly314 is coupled to the track mount assembly 316 by a shoulder joint. Theelbow joint, redundant joint, and shoulder joint may include a gearbox,which may be configured to drive rotational movement of the elbowassembly 313 in a fourth rotational axis (axis 4), the redundant-jointassembly 311 in a third rotational axis (axis 3), and the shoulderassembly 314 in a second rotational axis (axis 2), respectively. Thegearboxes of the elbow joint, redundant joint, and shoulder joint mayfacilitate translational movement of the LINAC 203 in a two-dimensionalhorizontal plane, for example, in the (x-, y-) plane parallel with thefloor. The track mount assembly 316 and track 317 facilitatetranslational movement of the LINAC 203 in a substantially vertical,linear axis (axis 1). The substantially vertical, linear axis (z-) maybe substantially perpendicular to the two dimensional horizontal plane(x-, y-).

In this embodiment, the track 317 is mounted to a vertical side of acolumn 318. The column 318 may be secured or mounted to the floor of thetreatment room during therapeutic radiation treatment or below the floorin a pit. In another embodiment, column 318 may be secured or mounted tothe ceiling of the treatment room during therapeutic radiationtreatment. Alternatively, the track 317 may be vertically mounted toother structures known to those skilled in the art, such as a wall,pedestal, block, or base structure.

A controller 201 is coupled to the robotic arm 302 to move the roboticarm 302 and the LINAC 203 in the seven DOF. The robotic arm 302,controlled by the controller 201, facilitate the positioning andorienting of the LINAC 203 using six rotational DOF, and onetranslational substantially vertical, linear DOF. Like the robotic arm202, the six rotational and one substantially horizontal, linear DOF ofthe robotic arm 302 of the robotic treatment delivery system 200 mayposition the LINAC 203 in substantially any place in a desired treatmentarea, such as a workspace, within the mechanical range of motion of therobotic arm 302. The robotic arm 302 may position the LINAC 203 to havea TCP in multiple locations within the workspace or treatment area.

In one embodiment, the robotic arm 302 is configured to move the LINAC203 along a single axis without moving the LINAC 203 along the otheraxes throughout an entire range of motion of the LINAC 203. For example,the first DOF is configured to move the LINAC 203 along a substantiallylinear axis through substantially an entire range of motion of therobotic arm without movement of the LINAC 203 along the four, five, orsix rotational DOF. The first DOF is the DOF that is closest to the baseend of the robotic arm. The base end is where the robotic arm 302 ismounted to the column 318. Alternatively, the base end is where therobotic arm 302 is mounted to the floor, ceiling, wall, or othermounting locations in the treatment room. The LINAC 203 is coupled tothe robotic arm 202 at the end-effector end of the robotic arm 302, alsoreferred to as the business end of the robotic arm 302.

In one embodiment, the controller 201 is configured to move the roboticarm 302 in along the first axis 331 of the first DOF. The first DOF isconfigured to move the other six rotational DOF of the robotic arm 302.The controller moves the robotic arm 302 up and down along the axis 331to different positions. For example, the robotic arm 302 may bepositioned in the first position 321, as illustrated in FIG. 3A, and inthe second position 323, as illustrated in FIG. 3B. As illustrated inFIGS. 3A and 3B, the robotic arm 302 can be configured to move the LINAC203, as well as the robotic arm 302, along the substantially vertical,linear axis (e.g., axis 331) throughout substantially an entire range ofmotion of the LINAC 203 without movement of the LINAC 203 along the sixrotational DOF.

In another embodiment, the robotic arm 302 has a substantially linearDOF that is horizontal. In another embodiment, the robotic arm 302 hasfour rotational DOF and one substantially linear DOF, and the first DOFis the substantially linear DOF that is configured to move the otherfour rotational DOF of the robotic arm. In this embodiment, thecontroller can move the LINAC along the substantially linear axis (e.g.,axis 331 or a horizontal first axis) throughout substantially an entirerange of motion of the LINAC 203 without movement of the LINAC 203 alongthe four rotational DOF. In the embodiment of the first DOF beinghorizontal, the controller is configured to move the LINAC 203 along asubstantially horizontal line in the mutually orthogonal horizontalcoordinate axes (e.g., x- and y-axes) that are substantiallyperpendicular to the vertical axis (e.g., z-axis). In the embodiment ofthe first DOF being vertical, the controller is configured to move theLINAC 203 along a substantially vertical line in the vertical axis(e.g., z-axis) that is substantially perpendicular to the mutuallyorthogonal horizontal coordinate axes (e.g., x- and y-axes).

FIG. 3C illustrates another embodiment of a robotic treatment deliverysystem 350 including a robotic arm having six degrees of freedomhorizontally mounted on a linear track 353 for a seventh degree offreedom. It should be nod that although the linear track 353 isdescribed as the seventh DOF, the linear track 353 can also be referredto the first DOF, since the first DOF is typically the DOF closest tothe base end of the robotic arm 352. The linear track 353 allows theentire robotic arm 352 to be moved from one position to another in thetreatment room, providing a seventh DOF in addition the six DOF of therobotic arm 352. The robotic treatment delivery system 350 includes ahorizontally-mounted robotic arm 352 having six degrees of freedom, andthe LINAC 203 coupled to the robotic arm 352. The robotic arm 352 ishorizontally mounted to a linear track 353 having, for example, rails354 that allow the robotic arm 352 to be translated along a linear axis.The robotic arm 352 may be coupled to a track mount assembly thatengages with the rails 354 to allow the robotic arm 352 to be movedalong the track 353. Alternatively, other types of mechanism may be usedto allow the robotic arm 352 to be moved along the track 353, as wouldbe appreciated by one of ordinary skill in the art. In anotherembodiment, the track 353 is a non-linear track. The controller (notillustrated) is configured to move the robotic arm 352 and the LINAC 203in the seven DOF, including one translational DOF (e.g., substantiallyhorizontal), and the six rotational DOF of the robotic arm 352. Thecontroller can move the robotic arm 352 along a single axis (ornon-linear path) without moving the other DOF of the robotic arm 352throughout an entire range of motion of the LINAC 203. In effect, theseventh DOF allows the entire frame of reference to be shifted.

Although the embodiment described above is a horizontally-mounted, sixDOF robotic arm 352 that is mounted to a floor, other configurations arepossible. For example, the linear track 353 may be mounted to a ceilingor to a pit within the floor. Also, in other embodiments, the track maybe vertically mounted to a column, a wall, or the like. In otherembodiments, the robotic arm 352 includes a redundant degree of freedom,as described herein. In one embodiment, the robotic arm 352 includes sixdegrees of freedom, one of the six being a redundant DOF, and theseventh DOF is the track. In another embodiment, the robotic arm 352includes seven DOF, one of the seven being a redundant DOF, and theeighth DOF is the track. Alternatively, the robotic arm 352 may includemore than one redundant DOF.

Using just a six DOF robotic arm, the workspace, which is representativeof the operating envelop of the robotic arm may be non-symmetric aboutthe patient because of interference and reachability issues. Forexample, if the robotic arm is disposed on one side of the patient, theLINAC may not be positioned in certain positions because it would beobstructed by the patient, the treatment couch, or other objects withinthe room. The linear track 353 can enable the robotic arm 353 to bepositioned on both sides of the treatment couch, creating a symmetricworkspace. The linear track 353 may also enable an expanded workspace,allowing the LINAC 203 to be positioned in more positions that werepreviously obstructed or avoided due to the proximity of the patient.The linear track 353 may also expand the workspace by moving the roboticarm 353 closer to or further away from the patient. This may beanalogous to someone lifting a heavy object wither with one's armstretched out or too close to one's body. If it's too close, one mightstep farther away, and if it's too far away, one might step closer tothe object. Since uniquely positioning the LINAC 203 in space may bedone with the six DOF, the flexibility provided by the seventh DOF(e.g., track) can be used for positioning the robotic arm 352 to avoidobstacles or other interferences in the treatment room, for a givenposition of the LINAC 203. The seventh DOF may also provide moredesirable positions for the robotic arm 352, for example, to avoidreaching over and across the patient. The seventh DOF may also optimizetime of travel based on positions of the robotic arm 352. For example,the robotic arm 352 may be moved along the linear DOF without moving theother DOFs. It should be noted that all of these capabilities may beperformed at the same time, but in one embodiment, the controller may gothrough a list of these capabilities according to priority, such as anordered list.

The treatment delivery systems 300 and 350 may be used in conjunctionwith an imaging system, a motion tracking system, and a patientpositioning system, as described with respect to FIG. 1.

In one embodiment, components of the robotic arm 202 or robotic arm 302may include touch-sensing material on the components' exterior. Inanother embodiment, the exterior of the components may be coated withcontact foam. Alternatively, other materials may be used to preventcomponents of the robotic arm 202 or 302 from crushing or knocking overthe operator. Specific details regarding the touch-sensing material andcontact foam that are known to those of ordinary skill in the art havenot been included as to not obscure the discussion regarding coating theexterior of the robotic arms 202 and 302 with material to prevent theoperator from being knocked over or crushed by the robotic arms.

In one embodiment, the robotic arms of FIGS. 1, 2, 3A, and 3B mayinclude components manufactured by KUKA Roboter GmbH of Germany.Alternatively, the components of the robotic arms may include othertypes of components.

FIG. 4A illustrates a top side view of a conventional robotic treatmentdelivery system 400 in a first position 401 relative to the treatmentcouch 206. The conventional robotic treatment delivery system 400includes the LINAC 103 coupled to the robotic arm 102. The robotic arm102 has two rigid links interconnected by a single elbow joint. TheLINAC 103 has been positioned to the first position 401 relative to thetreatment couch 206. At the first position 401, there is a distancemargin 410 between the treatment couch 206 and the LINAC 103 and roboticarm 102.

FIG. 4B illustrates a top side view of a robotic treatment system 450 inthe first position 401 relative to the treatment couch 206, according toone embodiment. The robotic treatment delivery system 450 includes theLINAC 203 coupled to the robotic arm 402. The robotic arm 402, unlikethe robotic arm 102, has three rigid links interconnected by two joints,an elbow joint, and a redundant joint. The robotic arm 102 has beenillustrated (dashed lines) in FIG. 4D for comparison purposes.

The LINAC 203 has been positioned to the same first position 401relative to the treatment couch 206. At the first position, there is adistance margin 420 between the treatment couch 206 and the LINAC 203and robotic arm 402. The distance margin 420 of the robotic treatmentdelivery system 450 is greater than the distance margin 410 of theconventional robotic treatment delivery system 400. The robotic arm 402,which includes a redundant joint, may position the LINAC 203 to increasethe distance margin between the robotic arm and other obstacles in thetreatment room. Not only is the distance margin 420 greater than thedistance margin 410, but the robotic arm 402 may position the LINAC 203to the first position 401 through a first path, which has a higherdistance margin between an obstacle (treatment couch 206) and therobotic arm 402 than a second path to the same position 401, such as thepath taken by the robotic arm 102 to position the LINAC 103.

The robotic arm 402 may position the LINAC 203 to have a TCP ortreatment target in multiple locations within the workspace or treatmentarea. The workspace or treatment area, however, may be limited bypositioning restrictions, for example, obstructions caused by a possiblecollision between either the LINAC 203, the treatment couch 206, ortheir corresponding robotic arms with components of the system, such asthe LINAC 203, treatment couch 206, imaging sources 207, detectors 208,and/or robotic arms 202 and 302 or obstructions of the radiation beam ofthe LINAC 203 with any of these above mentioned components. For example,the x-ray imaging sources 207 may prevent the LINAC 203 from beingpositioned where the x-ray imaging sources 207 are mounted becausepositioning it there would result in a possible collision (e.g.,collision obstructions). Similarly, the LINAC 203 may not be positionedunder the treatment couch 206 due to the placement of the detectors 208(e.g., collision obstructions). Another example of a positioningrestriction is obstructions of the radiation beam from the LINAC 203 dueto other components, for example, the detectors 208 and/or x-ray imagingsources 207 (e.g., beam obstructions). Another obstruction may be causedby the ground. Using the robotic arm having at least one redundantjoint, these positioning restrictions may be overcome. By overcoming thepositioning restrictions, the workspace may be increased because morenodes for positioning the LINAC 203 may become available, as describewith respect to FIG. 5. In addition to the increase in available nodesin the workspace, the robotic arm having at least one redundant jointmay increase the number of available paths to already existing nodes inthe workspace. Also, once the LINAC 203 has been positioned to aposition, one or more links of the robotic arm may be moved. Forexample, the one or more links may be moved to increase the distancemargin between the robotic arm and an obstacle in the treatment room,such as the treatment couch 206. In addition, using the one or morelinks having one or more redundant joints, the robotic arm may maneuverthe medical tool within a constrained volume without colliding withobstacles outside the constrained volume.

FIG. 4C illustrates a top side view of the conventional robotictreatment delivery system 400 of FIG. 4A in a second position 402relative to the treatment couch 206. If the robotic arm 102 were toposition the LINAC 203 to the second position 402, there would be acollision 430 between the robotic arm 102 and the treatment couch 206.As such, the second position 402 is an obstructed location and isunavailable as a possible node in the workspace.

FIG. 4D illustrates a top side view of the robotic treatment deliverysystem 450 of FIG. 4B in the second position 402 relative to thetreatment couch 206, according to one embodiment. Unlike the robotic arm102, the robotic arm 402 may position the LINAC 203 at the secondposition 402, which is considered a previously obstructed locationcaused by a positioning restriction, without a collision between therobotic arm 402 and the treatment couch 206. The robotic arm 102 hasbeen illustrated (dashed lines) in FIG. 4D for comparison purposes.

In another embodiment, movement of the robotic arm 402 and the roboticarm 221 may be dynamically coordinated. The dynamic coordination ofmovement between the treatment couch 206 and the LINAC 203 may increasea number of treatment targets within a mechanical range of motion of therobotic arm, may create a treatment target in a previously obstructedlocation caused by a positioning restriction within a mechanical rangeof motion of the robotic arm 402, or a positioning restriction within amechanical range of motion of the robotic arm 221. In one embodiment,the previously obstructed location may be caused by an obstruction of apossible collision, for example, between any two of the following: theLINAC 203, treatment couch 206, robotic arm 202, robotic arm 221, x-rayimaging sources 207, detectors 208, and/or other components of thesystem. Alternatively, the previously obstructed location may be causedby an obstruction of the radiation beam of the LINAC 203 with any of thefollowing: the robotic arm 202, robotic arm 221, x-ray imaging sources207, detectors 208, and/or other components of the system. In anotherembodiment, an anti-collision model may be embedded in the controller toensure that the patient is not positioned in an orientation and/orposition that might cause a possible collision between the treatmentcouch 206 including the patient's body and other moving parts of thesystem 400.

Using the robotic arm 402, the LINAC 203 may be positioned insymmetrical positions with respect to the treatment couch 206. Thecapability of positioning the LINAC 203 with respect to the treatmentcouch 206 in the symmetrical locations may lead to simplified paths forpath planning and contact avoidance planning, calculated beforetreatment delivery, such as calculated by a treatment planning systemduring treatment planning. The capability of positioning the LINAC 203with respect to the treatment couch 206 in symmetrical locations mayincrease the workspace within which the LINAC 203 may be positioned todirect radiation to a target. The access to direct radiation to targetswithin various locations of the patient may be increased because thenumber of nodes in the workspace is increased. For example, the nodes onone side of the treatment couch 206 may also be mirrored on the otherside of the treatment couch 206.

The total usable surface area may represent the positions or nodes inwhich the LINAC 203 may be positioned to emit radiation to the treatmenttarget of the patient. The total usable surface area of the robotictreatment delivery system 450, unlike the total usable surface area ofthe robotic treatment delivery system 400, is not limited by positioningrestrictions as described above. Using the robotic arm 402, thepositioning restrictions may be reduced or eliminated. Alternatively,using the robotic arm 202 or 302, the positioning restrictions may bereduced or eliminated.

It should be noted that the unreachable area of the robotic treatmentdelivery system 400 cannot be cured by merely mounting the robotic arm102 on the opposite side of the treatment couch 206 because the oppositeside will then have the unreachable area due to the obstruction of thetreatment couch 206 and the robotic arm 102. In other words, merelymounting the robot-based radiosurgery system on another side does notovercome the positioning restriction due to the obstruction causing theunreachable area of the robotic treatment delivery system 400.

FIG. 5 is a perspective drawing illustrating a workspace 511 of arobotic treatment delivery system 200 or 300, according to oneembodiment. As described above, a collection of spatial nodes andassociated safe paths interconnecting these spatial nodes is called a“workspace” or “node set”. The workspace is representative of theoperating envelop of the robotic arm. The workspace 511 includes a setof spatial nodes 511, which reside on the surface of the workspace 511,at which to position the radiation source. Each of the spatial nodes 511are represented by a “+” symbol (only a couple are labeled). The spatialnodes 511 represent spatial nodes at which the conventional treatmentdelivery systems can be positioned. A workspace or node set, asdescribed above, is a collection of spatial nodes and associated safepaths interconnecting these spatial nodes. However, unlike the workspaceof conventional systems, the workspace 511 and the number of spatialnodes may be increased using the treatment delivery systems 200 or 300.As such, the workspace 511 also includes a set of additional orincreased spatial nodes 512, as illustrated as dashed “+”. The totalnumber of spatial nodes 511 and increased spatial nodes 512 of theworkspace 511 is greater than the total number of spatial nodes 511 ofthe workspace of a conventional system.

By moving the LINAC 203 using the robotic arm 202 or 302, the LINAC 203may access certain zones (e.g., spatial nodes) around the treatmentcouch 206 that were previously blocked or otherwise unreachable inconventional systems. For example, the conventional robotic arm couldnot position the LINAC 103 around the treatment couch 106 to positionthe LINAC 103 in certain positions. These blocked positions, however,are not blocked and are reachable for the treatment delivery systems 200and 300, as described herein. Having greater accessibility to thosecertain zones, which were previously blocked or otherwise unreachable bythe treatment couch in conventional systems, increases the workspace 511(e.g., spatial nodes at which the LINAC 203 may deliver radiation to thetarget). Moreover, additional spatial nodes may be accessed that werenot accessible by conventional robotic arms because of the distancemargin between the conventional robotic arm and the patient.

It should be noted that although workspace 511 is spherical,alternatively, the workspace 511 may have other geometries (e.g.,elliptical) and defined for VOIs residing in the head of a patient, orwithin other areas of a patient. Additionally, multiple workspaces maybe defined for different portions of a patient, each having differentradius or source axis distances (SADs), such as 650 mm and 800 mm. TheSAD is the distance between the collimator in the LINAC 203 and thetarget within the VOI. The SAD defines the surface area of theworkspace. In one embodiment of an elliptical workspace, the SAD mayrange from 900 mm to 1000 mm. Other SADs may be used.

Spatial nodes 511 and increase spatial nodes 512 reside on the surfaceof workspace 511. Spatial nodes represent positions where the LINAC 203is pre-programmed to stop and delivery a dose of radiation to the VOIwithin the patient. During delivery of a treatment plan, robotic arm 202moves the LINAC 203 to each and every spatial node 112 and 412, where adose is determined to be delivered, following a predefined path. Thepredefine path may also include some spatial nodes 511 and 512 where nodose needs to be delivered, in order to simplify the motions of therobotic arm 202 or 302.

The node set may include spatial nodes that are substantially uniformlydistributed over the geometric surface of workspace 511. The node setincludes all programmed spatial nodes 511 and 412 and provides aworkable number of spatial nodes 511 and 512 for effectively computingtreatment plan solutions for most ailments and associated VOIs. The nodeset provides a reasonably large number of spatial nodes 511 and 512 suchthat homogeneity and conformality thresholds can be achieved for a largevariety of different VOIs, while providing enough vantage points toavoid critical structures within patients. Using the embodimentsdescribed herein, the number of spatial nodes is greater than the numberof spatial nodes in the conventional systems. It should be appreciatedthat the node set may include more or less spatial nodes 511 and 512than is illustrated or discussed. For example, as processing powerincreases and experience gained creating treatment plans, the averagenumber of spatial nodes 511 and 512 may increase with time to providegreater flexibility and higher quality treatment plans.

During radiation treatment, the patient rests on treatment couch 206,which is maneuvered to position a volume of interest (“VOI”) containinga target to a preset position or within an operating range accessible toradiation source of the LINAC 203. The robotic arm 202 or 302 has sevenDOF capable of positioning the LINAC 203 with almost an infinite numberof positions and orientations within its operating envelope.

As described above, the embodiments described herein have been depictedand described as robotic arms coupled to a LINAC, however, in otherembodiments, other robotic manipulators and/or other medical tools maybe used. For example, the medical tool may be an imaging source of animager, a surgical tool, an implantation tool, a treatment couch. In thecase of a treatment couch, the robotic arm may position the treatmentcouch like the LINAC described above to increase a distance marginbetween the robotic arm and other obstacles in the treatment room, toincrease the available workspace, or the like.

The embodiments described herein may allow the LINAC 203 to bepositioned at various positioned to direct one or more radiation beamstowards a patient on a treatment couch. For example, the LINAC 203 maybe positioned to a first position to direct radiation to a target withinthe head of a patient that is lying on the treatment couch.Alternatively, the LINAC 203 may be positioned to a second position todirect radiation to a target within the patient for a posteriortreatment. During posterior treatments, with the patient lying in supineposition on the treatment couch, the LINAC 203 may be positioned to bepointed upwards at the patient and deliver the treatment beam from theposterior direction. The LINAC 203 may also be moved to a differentlocation, or in a different orientation at the same location by movingthe position and/or orientation at the same location. For example, therobotic arm can position and orient the LINAC 203 above the patientusing the substantial vertical, linear DOF (e.g., track 226) and theadditional DOF (e.g., redundant-joint, elbow, and shoulder assemblies)to provide the vertical reach, while the wrist assembly 212 provides theorientation of the LINAC 203 with respect to a target in a posteriortreatment (e.g., rotate the LINAC 203 about the pitch-axis using thetool-yaw joint of the wrist assembly 212). Alternatively, the LINAC 203may be positioned and oriented with respect to the target in posteriortreatments using other motions of the robotic arm 202. Alternatively,the LINAC 203 at the position 283 is configured to direct radiation to atarget in other types of treatments.

FIG. 6 illustrates one embodiment of a method 600 for positioning amedical tool using a robotic manipulator. The method 600 includesproviding a medical tool (e.g., LINAC 203) coupled to a roboticmanipulator having seven or more DOF, operation 601, and moving themedical tool along seven or more DOF using the robotic manipulator,operation 602.

Moving the medical tool along the seven or more DOF includes moving themedical moving the medical tool in four rotational axes fortranslational movement of the medical tool along mutually orthogonal x-,y-, and z-coordinate axes, and in three rotational axes for roll-,pitch-, and yaw-rotations of the medical tool about x-, y-, and z-axes,respectively. In one embodiment, the medical tool can be positioned to afixed position by moving the medical tool using the four rotationalaxes, and oriented at the fixed position using the three rotationalaxes. The medical tool may also be moved along a substantially linearDOF. The substantially linear DOF may be in addition to, in place of oneof the rotational DOF described above. In on embodiment, the medicaltool is moved along a substantially vertical, linear DOF having asubstantially linear axis for translational movements of the medicaltool along a substantially vertical line in a z-axis that issubstantially perpendicular to horizontal coordinate x- and y-axes. Inanother embodiment, the medical tool is moved along a substantiallyhorizontal, linear DOF having a substantially linear axis fortranslational movements of the medical tool along a horizontal line inthe mutually orthogonal horizontal coordinate x- and y-axes that issubstantially perpendicular to the z-axis. The medical tool may be movedalong a substantially linear axis throughout substantially an entirerange of motion of the medical tool without moving the medical tool inthe six (for seven DOF) or seven (for eight DOF) rotational DOF.

In another embodiment, the medical tool can be rotated about the z-axis,y-axis, and y-axis using a tool-yaw joint, a tool-pitch joint, and atool-roll joint of a robotic manipulator. The medical tool can also berotated about first, second, and third rotational axes using a redundantjoint, an elbow joint, and a first shoulder joint, respectively, of therobotic manipulator. The medical tool can be either rotating about afourth rotational axis using a second shoulder joint or translated abouta substantially linear axis using a track and a track mount assembly forthe seventh DOF.

In another embodiment, the medical tool can be positioned to a fixedposition using a robotic manipulator, and maintained at the fixedposition, while moving the robotic manipulator. The medical tool can bepositioned within a constrained volume without colliding with an objectoutside of the constrained volume.

The method may also include positioning the medical tool to a previouslyobstructed location caused by a position restriction within a mechanicalrange of motion of the robotic manipulator and the medical tool. Inanother embodiment, the medical tool is positioned from a first positionto a second position through a first path, instead of through anobstructed path caused by an obstacle to the same second position. Inanother embodiment, the medical tool is positioned from a first positionto a second position through a first path, the first path having ahigher distance margin between an obstacle and the robotic manipulatorand medical tool than a second path to the same second position.

FIG. 7 illustrates another embodiment of a method for maintaining amedical tool at the fixed position. The method includes positioning amedical tool to a fixed position using a robotic manipulator, operation701; and maintaining the medical tool at the fixed position, whilemoving the robotic manipulator, operation 702. In one embodiment, therobotic manipulator includes multiple rigid links interconnected byjoints. While the medical tool is maintained at the fixed position, oneor more of the rigid links of the robotic manipulator may be moved. Themedical tool can be positioned within a constrained volume withoutcolliding with an object outside of the constrained volume.

In another embodiment, the method includes providing an imaging systemhaving an imaging field of view, and maintaining the LINAC 203substantially outside of the imaging field of view for all supportedtreatment positions.

In one embodiment, moving the LINAC 203 and the treatment couch 206 mayinclude dynamically coordinating an orientation and position of theLINAC 203 and the treatment couch 206 using the controller. In anotherembodiment, moving the LINAC 203 and the treatment couch 206 includesaligning a radiation source of the LINAC 203 with a treatment targetwithin a patient disposed on the treatment couch 206. In anotherembodiment, moving the LINAC 203 and the treatment couch 206 furtherincludes positioning the LINAC 203 and the treatment couch 206 to createa treatment target in a previously obstructed location within amechanical range of motion of the robotic arm 202 and the LINAC 203.

FIG. 8 illustrates a block diagram of one embodiment of a treatmentsystem 800 that may be used to perform radiation treatment in whichembodiments of the present invention may be implemented. The depictedtreatment system 800 includes a diagnostic imaging system 810, atreatment planning system 830, and a treatment delivery system 850. Inother embodiments, the treatment system 800 may include fewer or morecomponent systems.

The diagnostic imaging system 810 is representative of any systemcapable of producing medical diagnostic images of a volume of interest(VOI) in a patient, which images may be used for subsequent medicaldiagnosis, treatment planning, and/or treatment delivery. For example,the diagnostic imaging system 810 may be a computed tomography (CT)system, a single photon emission computed tomography (SPECT) system, amagnetic resonance imaging (MRI) system, a positron emission tomography(PET) system, a near infrared fluorescence imaging system, an ultrasoundsystem, or another similar imaging system. For ease of discussion, anyspecific references herein to a particular imaging system such as a CTx-ray imaging system (or another particular system) is representative ofthe diagnostic imaging system 810, generally, and does not precludeother imaging modalities, unless noted otherwise.

The illustrated diagnostic imaging system 810 includes an imaging source812, an imaging detector 814, and a processing device 816. The imagingsource 812, imaging detector 814, and processing device 816 are coupledto one another via a communication channel 818 such as a bus. In oneembodiment, the imaging source 812 generates an imaging beam (e.g.,x-rays, ultrasonic waves, radio frequency waves, etc.) and the imagingdetector 814 detects and receives the imaging beam. Alternatively, theimaging detector 814 may detect and receive a secondary imaging beam oran emission stimulated by the imaging beam from the imaging source(e.g., in an MRI or PET scan). In one embodiment, the diagnostic imagingsystem 810 may include two or more diagnostic imaging sources 812 andtwo or more corresponding imaging detectors 814. For example, two x-raysources 812 may be disposed around a patient to be imaged, fixed at anangular separation from each other (e.g., 90 degrees, 45 degrees, etc.)and aimed through the patient toward corresponding imaging detectors814, which may be diametrically opposed to the imaging sources 814. Asingle large imaging detector 814, or multiple imaging detectors 814,also may be illuminated by each x-ray imaging source 814. Alternatively,other numbers and configurations of imaging sources 812 and imagingdetectors 814 may be used.

The imaging source 812 and the imaging detector 814 are coupled to theprocessing device 816 to control the imaging operations and processimage data within the diagnostic imaging system 810. In one embodiment,the processing device 816 may communicate with the imaging source 812and the imaging detector 814. Embodiments of the processing device 816may include one or more general-purpose processors (e.g., amicroprocessor), special purpose processors such as a digital signalprocessor (DSP), or other type of devices such as a controller or fieldprogrammable gate array (FPGA). The processing device 816 also mayinclude other components (not shown) such as memory, storage devices,network adapters, and the like. In one embodiment, the processing device816 generates digital diagnostic images in a standard format such as theDigital Imaging and Communications in Medicine (DICOM) format. In otherembodiments, the processing device 816 may generate other standard ornon-standard digital image formats.

Additionally, the processing device 816 may transmit diagnostic imagefiles such as DICOM files to the treatment planning system 830 over adata link 860. In one embodiment, the data link 860 may be a directlink, a local area network (LAN) link, a wide area network (WAN) linksuch as the Internet, or another type of data link. Furthermore, theinformation transferred between the diagnostic imaging system 810 andthe treatment planning system 830 may be either pulled or pushed acrossthe data link 860, such as in a remote diagnosis or treatment planningconfiguration. For example, a user may utilize embodiments of thepresent invention to remotely diagnose or plan treatments despite theexistence of a physical separation between the system user and thepatient.

The illustrated treatment planning system 830 includes a processingdevice 832, a system memory device 834, an electronic data storagedevice 836, a display device 838, and an input device 840. Theprocessing device 832, system memory 834, storage 836, display 838, andinput device 840 may be coupled together by one or more communicationchannel 842 such as a bus.

The processing device 832 receives and processes image data. Theprocessing device 832 also processes instructions and operations withinthe treatment planning system 830. In certain embodiments, theprocessing device 832 may include one or more general-purpose processors(e.g., a microprocessor), special purpose processors such as a digitalsignal processor (DSP), or other types of devices such as a controlleror field programmable gate array (FPGA).

In particular, the processing device 832 may be configured to executeinstructions for performing treatment operations discussed herein. Forexample, the processing device 832 may identify a non-linear path ofmovement of a target within a patient and develop a non-linear model ofthe non-linear path of movement. In another embodiment, the processingdevice 832 may develop the non-linear model based on multiple positionpoints and multiple direction indicators. In another embodiment, theprocessing device 832 may generate multiple correlation models andselect one of the models to derive a position of the target.Furthermore, the processing device 832 may facilitate other diagnosis,planning, and treatment operations related to the operations describedherein.

In one embodiment, the system memory 834 may include random accessmemory (RAM) or other dynamic storage devices. As described above, thesystem memory 834 may be coupled to the processing device 832 by thecommunication channel 842. In one embodiment, the system memory 834stores information and instructions to be executed by the processingdevice 832. The system memory 834 also may be used for storing temporaryvariables or other intermediate information during execution ofinstructions by the processing device 832. In another embodiment, thesystem memory 834 also may include a read only memory (ROM) or otherstatic storage device for storing static information and instructionsfor the processing device 832.

In one embodiment, the storage 836 is representative of one or more massstorage devices (e.g., a magnetic disk drive, tape drive, optical diskdrive, etc.) to store information and instructions. The storage 836and/or the system memory 834 also may be referred to as machine readablemedia. In a specific embodiment, the storage 836 may store instructionsto perform the modeling operations discussed herein. For example, thestorage 836 may store instructions to acquire and store data points,acquire and store images, identify non-linear paths, develop linearand/or non-linear correlation models, and so forth. In anotherembodiment, the storage 836 may include one or more databases.

In one embodiment, the display 838 may be a cathode ray tube (CRT)display, a liquid crystal display (LCD), or another type of displaydevice. The display 838 displays information (e.g., a two-dimensional or3D representation of the VOI) to a user. The input device 840 mayinclude one or more user interface devices such as a keyboard, mouse,trackball, or similar device. The input device(s) 840 may also be usedto communicate directional information, to select commands for theprocessing device 832, to control cursor movements on the display 838,and so forth.

Although one embodiment of the treatment planning system 830 isdescribed herein, the described treatment planning system 830 is onlyrepresentative of an exemplary treatment planning system 830. Otherembodiments of the treatment planning system 830 may have many differentconfigurations and architectures and may include fewer or morecomponents. For example, other embodiments may include multiple buses,such as a peripheral bus or a dedicated cache bus. Furthermore, thetreatment planning system 830 also may include Medical Image Review andImport Tool (MIRIT) to support DICOM import so that images can be fusedand targets delineated on different systems and then imported into thetreatment planning system 830 for planning and dose calculations. Inanother embodiment, the treatment planning system 830 also may includeexpanded image fusion capabilities that allow a user to plan treatmentsand view dose distributions on any one of the various imaging modalitiessuch as MRI, CT, PET, and so forth. Furthermore, the treatment planningsystem 830 may include one or more features of convention treatmentplanning systems.

In one embodiment, the treatment planning system 830 may share adatabase on the storage 836 with the treatment delivery system 850 sothat the treatment delivery system 850 may access the database prior toor during treatment delivery. The treatment planning system 830 may belinked to treatment delivery system 850 via a data link 870, which maybe a direct link, a LAN link, or a WAN link, as discussed above withrespect to data link 860. Where LAN, WAN, or other distributedconnections are implemented, any of components of the treatment system800 may be in decentralized locations so that the individual systems810, 830 and 850 may be physically remote from one other. Alternatively,some or all of the functional features of the diagnostic imaging system810, the treatment planning system 830, or the treatment delivery system850 may be integrated with each other within the treatment system 800.

The illustrated treatment delivery system 850 includes a radiationsource 852, an imaging system 854, a processing device 856, and atreatment couch 858. The radiation source 852, imaging system 854,processing device 856, and treatment couch 858 may be coupled to oneanother via one or more communication channels 860. One example of atreatment delivery system 850 is shown and described in more detail withreference to FIG. 4A.

In one embodiment, the radiation source 852 is a therapeutic or surgicalradiation source 852 to administer a prescribed radiation dose to atarget volume in conformance with a treatment plan. In one embodiment,the radiation source 852 is the LINAC 203, as described herein.Alternatively, the radiation source 852 may be other types of radiationsources as would be appreciated by those of ordinary skill in the art.For example, the target volume may be an internal organ, a tumor, aregion. As described above, reference herein to the target, targetvolume, target region, target area, or internal target refers to anywhole or partial organ, tumor, region, or other delineated volume thatis the subject of a treatment plan.

In one embodiment, the imaging system 854 of the treatment deliverysystem 850 captures intra-treatment images of a patient volume,including the target volume, for registration or correlation with thediagnostic images described above in order to position the patient withrespect to the radiation source. Similar to the diagnostic imagingsystem 810, the imaging system 854 of the treatment delivery system 850may include one or more sources and one or more detectors.

The treatment delivery system 850 also may include a processing device856 to control the radiation source 852, the imaging system 854, and atreatment couch 858, which is representative of any patient supportdevice. In one embodiment, the treatment couch 858 is the treatmentcouch 206 coupled to the robotic arm 202 or 302, as described herein. Inanother embodiment, the treatment couch 858 is the treatment couchcoupled to the robotic arm 106, as described herein. Alternatively,other types of patient support devices can be used. In one embodiment,the radiation source 852 is coupled to a first robotic arm (e.g.,robotic arm 202), and the treatment couch 858 is coupled to a secondrobotic arm (e.g., robotic arm 221). The first and second robotic armsmay be coupled to the same controller (e.g., controller) or to separatecontrollers. In one embodiment, the first and second robotic arms areidentical robotic arms. In one embodiment, each of the first and secondrobotic arms includes four rotational DOF and one substantially linearDOF. In another embodiment, each of the first and second robotic armsincludes five rotational DOF and one substantially linear DOF.Alternatively, each of the first and second robotic arms includes sixrotational DOF and one substantially linear DOF. Alternatively, thefirst and second robotic arms may include dissimilar number and types ofDOF. In another embodiment, the first and second robotic arms aredissimilar types of robotic arms. Alternatively, only the first roboticarm is used to move the LINAC 203 with respect to the treatment couch206.

The processing device 856 may include one or more general-purposeprocessors (e.g., a microprocessor), special purpose processors such asa digital signal processor (DSP), or other devices such as a controlleror field programmable gate array (FPGA). Additionally, the processingdevice 856 may include other components (not shown) such as memory,storage devices, network adapters, and the like.

The illustrated treatment delivery system 850 also includes a userinterface 862 and a measurement device 864. In one embodiment, the userinterface 862 is the user interface 500. In another embodiment, the userinterface 862 is the graphical user interface 600. In one embodiment,the user interface 862 allows a user to interface with the treatmentdelivery system 850. In particular, the user interface 862 may includeinput and output devices such as a keyboard, a display screen, and soforth. The measurement device 864 may be one or more devices thatmeasure external factors such as the external factors described above,which may influence the radiation that is actually delivered to thetarget region 20. Some exemplary measurement devices include athermometer to measure ambient temperature, a hygrometer to measurehumidity, a barometer to measure air pressure, or any other type ofmeasurement device to measure an external factor.

In the foregoing specification, embodiments of the invention have beendescribed with reference to specific exemplary embodiments thereof. Itwill, however, be evident that various modifications and changes may bemade thereto without departing from the broader spirit and scope of thepresent embodiments as set forth in the claims. The specification anddrawings are, accordingly, to be regarded in an illustrative rather thana restrictive sense.

1. An apparatus, comprising: a medical tool; and a robotic manipulatorcoupled to the medical tool to move the medical tool along seven or moredegrees of freedom (DOF), wherein the seven or more DOF comprises atleast one redundant DOF.
 2. The apparatus of claim 1, wherein therobotic manipulator comprises a plurality of rigid links interconnectedby joints allowing either rotational motion or translationaldisplacement, and wherein at least one of the joints is a redundantjoint that moves the robotic manipulator in the at least one redundantDOF.
 3. The apparatus of claim 2, wherein the robotic manipulator is arobotic arm, and wherein the robotic manipulator comprises: a wristassembly coupled to the medical tool to move the medical tool in threeDOF; and an arm assembly coupled to the wrist assembly to move themedical tool in four DOF, wherein the four DOF comprise the at least oneredundant DOF.
 4. The apparatus of claim 3, wherein the wrist assemblycomprises: a tool-yaw joint coupled to a mounting plate that supportsthe medical tool to rotate the medical tool along a first rotationalaxis; a tool-pitch joint coupled to the tool-yaw joint to rotate themedical tool along a second rotational axis; and a tool-roll jointcoupled to the tool-pitch joint to rotate the medical tool along a thirdrotational axis.
 5. The apparatus of claim 4, wherein the arm assemblycomprises: an elbow assembly; a redundant-joint assembly coupled betweenthe wrist assembly and the elbow assembly; a first shoulder assemblycoupled to the elbow assembly; and a second shoulder assembly coupled tothe first shoulder assembly.
 6. The apparatus of claim 5, furthercomprising: a redundant joint coupled to the redundant-joint assemblyand the elbow assembly, wherein the redundant joint comprises a gearboxto drive rotational movement of the robotic arm in a fourth rotationalaxis of the robotic arm; an elbow joint coupled to the elbow assemblyand the first shoulder assembly, wherein the elbow joint comprises anelbow gearbox to drive rotational movement of the robotic arm in a fifthrotational axis of the robotic arm; a first shoulder joint coupled tothe first shoulder assembly and the second shoulder assembly, whereinthe first shoulder joint comprises a first shoulder gearbox to driverotational movement of the robotic arm in a sixth rotational axis of therobotic arm; and a second shoulder joint coupled to the second shoulderassembly and a mount assembly, wherein the second shoulder jointcomprises a second shoulder gearbox to drive rotational movement of therobotic arm in a seventh rotational axis of the robotic arm.
 7. Theapparatus of claim 6, further comprising: a track mount assembly coupledto the second shoulder assembly of the robotic arm; and a track coupledto the track mount assembly, wherein the track is configured to move thetrack mount assembly along an eighth translational axis of the roboticarm.
 8. The apparatus of claim 4, wherein the arm assembly comprises: anelbow assembly coupled to the wrist assembly; a first shoulder assemblycoupled to the elbow assembly; a second shoulder assembly coupled to thefirst shoulder assembly, an elbow joint coupled to the elbow assemblyand the first shoulder assembly, wherein the elbow joint comprises anelbow gearbox to drive rotational movement of the robotic arm in afourth rotational axis of the robotic arm; a first shoulder jointcoupled to the first shoulder assembly and the second shoulder assembly,wherein the first shoulder joint comprises a first shoulder gearbox todrive rotational movement of the robotic arm in a fifth rotational axisof the robotic arm; a second shoulder joint coupled to the secondshoulder assembly and a mount assembly, wherein the second shoulderjoint comprises a second shoulder gearbox to drive rotational movementof the robotic arm in a sixth rotational axis of the robotic arm; and aredundant joint coupled to the first and second shoulder assemblies,wherein the redundant joint comprises a third shoulder gearbox to driverotational movement of the robotic arm in a seventh rotational axis ofthe robotic arm.
 9. The apparatus of claim 4, wherein the arm assemblycomprises: an elbow assembly coupled to the wrist assembly; a firstshoulder assembly coupled to the elbow assembly; a redundant-jointassembly coupled between the elbow assembly and the first shoulderassembly; and a second shoulder assembly coupled to the first shoulderassembly.
 10. The apparatus of claim 9, further comprising: an elbowjoint coupled to the wrist assembly and the elbow assembly, wherein theelbow joint comprises an elbow gearbox to drive rotational movement ofthe robotic arm in a fourth rotational axis of the robotic arm; aredundant joint coupled to the elbow assembly and the first shoulderassembly, wherein the redundant joint comprises a gearbox to driverotational movement of the robotic arm in a fifth rotational axis of therobotic arm; a first shoulder joint coupled to the first shoulderassembly and the second shoulder assembly, wherein the first shoulderjoint comprises a first shoulder gearbox to drive rotational movement ofthe robotic arm in a sixth rotational axis of the robotic arm; and asecond shoulder joint coupled to the second shoulder assembly and amount assembly, wherein the second shoulder joint comprises a secondshoulder gearbox to drive rotational movement of the robotic arm in aseventh rotational axis of the robotic arm.
 11. The apparatus of claim1, wherein seven DOF of the seven or more DOF comprise: four rotationalaxes for translational movement of the medical tool along mutuallyorthogonal x-, y-, and z-coordinate axes; and three rotational axes forroll-, pitch-, and yaw-rotations of the medical tool about x-, y-, andz-axes, respectively.
 12. The apparatus of claim 11, further comprisesan eighth DOF, wherein the eighth DOF is a substantially linear DOF thatincludes a substantially linear axis for translational movement of themedical tool along the substantially linear axis.
 13. The apparatus ofclaim 12, wherein the substantially linear DOF is a first DOF of theeight DOF, wherein the first DOF is configured to move the other sevenrotational DOF of the robotic manipulator, and wherein the first DOF isthe DOF closest to the base end of the robotic arm.
 14. The apparatus ofclaim 1, wherein seven DOF of the seven or more DOF comprise: threerotational axes for translational movement of the medical tool alongmutually orthogonal x-, y-, and z-coordinate axes; three rotational axesfor roll-, pitch-, and yaw-rotations of the medical tool about x-, y-,and z-axes, respectively; and a translational axis for translationalmovement of the medical tool along a substantially linear axis.
 15. Theapparatus of claim 1, wherein the medical tool is a linear accelerator(LINAC).
 16. The apparatus of claim 15, wherein by moving the medicaltool along the seven or more DOF, including the at least one redundantDOF, the robotic manipulator increases a workspace of the LINAC, andwherein the workspace comprises a number of nodes at which the LINAC canbe positioned to deliver radiation to a target.
 17. The apparatus ofclaim 1, wherein the medical tool is an imaging source of an imager. 18.The apparatus of claim 1, wherein the medical tool is a surgical tool.19. The apparatus of claim 1, wherein the medical tool is animplantation tool.
 20. The apparatus of claim 1, wherein the medicaltool is a treatment couch.
 21. The apparatus of claim 1, furthercomprising a controller coupled to the robotic manipulator to move therobotic manipulator and the medical tool in the seven or more DOF.
 22. Amethod, comprising: providing a medical tool coupled to a roboticmanipulator having seven or more degrees of freedom (DOF), wherein theseven DOF comprise at least one redundant DOF; and moving the medicaltool using the robotic manipulator along seven or more degrees offreedom (DOF).
 23. The method of claim 22, wherein moving the medicaltool along the seven or more DOF comprises: moving the medical tool infour rotational axes for translational movement of the medical toolalong mutually orthogonal x-, y-, and z-coordinate axes; and moving themedical tool in three rotational axes for roll-, pitch-, andyaw-rotations of the medical tool about x-, y-, and z-axes,respectively.
 24. The method of claim 23, further comprising:positioning the medical tool to a fixed position by moving the medicaltool using the four rotational axes; and orienting the medical tool atthe fixed position by moving the medical tool using the three rotationalaxes.
 25. The method of claim 23, further comprising: positioning themedical tool to a fixed position using a robotic manipulator; andmaintaining the medical tool at the fixed position, while moving therobotic manipulator.
 26. The method of claim 23, further comprisingpositioning the medical tool to a previously obstructed location causedby a position restriction within a mechanical range of motion of therobotic manipulator and the medical tool.
 27. The method of claim 23,further comprising positioning the medical tool from a first position toa second position through a first path, instead of through an obstructedpath caused by an obstacle to the same second position.
 28. The methodof claim 23, further comprising positioning the medical tool from afirst position to a second position through a first path, wherein thefirst path has a higher distance margin between an obstacle and therobotic manipulator and medical tool than a second path to the samesecond position.
 29. The method of claim 23, further comprisingpositioning the medical tool within a constrained volume withoutcolliding with an object outside the constrained volume.
 30. The methodof claim 23, further comprising moving the medical tool along asubstantially linear DOF.
 31. A method, comprising: positioning amedical tool to a fixed position using a robotic manipulator; andmaintaining the medical tool at the fixed position, while moving therobotic manipulator.
 32. The method of claim 31, wherein the roboticmanipulator comprises a plurality of rigid links interconnected byjoints, and wherein maintaining the medical tool at the fixed positioncomprises moving one or more of the plurality of rigid links of therobotic manipulator, while maintaining the medical tool at the fixedposition.
 33. An apparatus, comprising: a medical tool; and means formoving the medical tool along seven or more degrees of freedom (DOF),wherein the seven DOF comprise at least one redundant DOF.
 34. Theapparatus of claim 33, wherein the medical tool is a linear accelerator(LINAC), and wherein the apparatus further comprises means forincreasing a workspace of the LINAC by moving the LINAC along the sevenor more DOF, including the at least one redundant DOF, wherein theworkspace comprises a number of nodes at which the LINAC can bepositioned to deliver radiation to a target.
 35. The apparatus of claim34, wherein the means for increasing the workspace comprises means forincreasing a distance margin between the LINAC and an obstacle whilepositioning the LINAC at a node to deliver radiation to the target. 36.The apparatus of claim 33, wherein the means for moving the medical toolalong the at least one redundant DOF increase a range of motion of themedical tool.
 37. The apparatus of claim 33, wherein the means formoving the LINAC along the seven or more DOF, including the at least oneredundant DOF, allows positioning the medical tool within a constrainedvolume without colliding with an object outside the constrained volume.38. The apparatus of claim 33, wherein the means for moving the LINACalong the seven or more DOF, including the at least one redundant DOF,allows positioning the medical tool from a first position to a secondposition through a first path, wherein the first path has a higherdistance margin between an obstacle and the means for moving the LINACthan a second path to the same second position.
 39. The apparatus ofclaim 33, further comprising: means for positioning the medical tool toa fixed position; and means for maintaining the tool at the fixedposition while moving the means for positioning the medical tool. 40.The apparatus of claim 39, wherein the means for maintaining the medicaltool at the fixed position increases a number of paths to position themedical tool to the fixed position.
 41. A system apparatus, comprising:a linear accelerator (LINAC); a robotic manipulator coupled to theLINAC, the robotic manipulator configured to move the LINAC in at leastseven degrees of freedom (DOF), wherein the at least seven DOF comprisesat least one redundant DOF; a controller coupled to the roboticmanipulator to control movement of the LINAC to align a radiation sourceof the LINAC with a treatment target; and an imaging system to generatea plurality of images of the treatment target.
 42. The system of claim41, wherein the controller is configured to position the LINAC to accessa treatment target in a previously obstructed location caused by aposition restriction within a mechanical range of motion of the roboticmanipulator and the LINAC.
 43. The system of claim 41, wherein therobotic manipulator comprises at least one redundant joint to move theLINAC in the at least one redundant DOF.
 44. The system of claim 41,wherein the imaging system comprises: a pair of x-ray sources; and apair of x-ray image detectors, wherein each image detector is disposedopposite a respective source.